Treatment of polymerized rosin and product obtained



Sept 14, 1943. R. F. B. cox 2,329,517

TREATMENT OF POLYMERIZED ROSIN AND PRODUCT OBTAINED Filed Dec. 15, 1942 RnFF//Mrf [x rfa/scr Sou/rm or 447050115 Bona .gg/f Res/own /PAFF//w rf- I I TRAc-r ff oRnx SoLur/o/v I f7-Hna Sau/rw Ex renc r/a/v TTORNEY `and modified rosins.

Patented Sept. 14, 1943 TREATMENT F POLYMERIZED ROSIN AND PRODUCT OBTAINED f Richard F. B. Cox, Wilmington, Del., assignor to Hercules Powder Company, Wilmington, Del., a corporation of Delaware Application December 15, 1942, Serial No. 469,070

12 Claims.

This invention relates to a process for the sepa; ration and recovery of resin acids from rosin Particularly it relates to a process for the recovery of a non-crystalline polymerized rosin product high in acid number and in melting point and low in unsaponiflable content.

Rosin acids have heretofore been separated from rosin by distillation, by crystallization of the acids, by crystallization of .the sodium acid abietate, and by extraction with alkalies. Distillation causes the rosin to isomerize to abietic acid, a very readily crystallizing acid, and the resulting rosin has a pronounced tendency to crystallize. Crystallization of the acids4 or the sodium acid abietate produces a crystalline rosin. Extraction of the acids by alkalies involves the subsequent acidification of the soap formed in order to free the rosin acids which is inconvenient and expensive. Moreover, these prior processes selectively remove abietic acid and abietic-like acids. and do not remove the rosin acids in the proportions in which they are present in the oroginal rosin.

Rosin which is substantially freed .of neutral bodies by following the present vinvention is adapted to many uses for which ordinary rosin, because of its lower melting point or its odor, is unsatisfactory.

The neutral bodies which can be removed from the rosin (say ordinary refined wood rosin) by applying the principles of the present invention usually amount to about by weight of the rosin. They are soft and iiuid and have a marked effect in lowering the melting point of the rosin. For example, a wood rosin which had a drop melting point of 80.5 C. before removal of the neutral bodies, melted at 88.7 C. after their removal by the process of the present invention. Likewise a gum rosin melted at 86.2 C. before removing the neutral bodies, and at 91.2 C. afterwards.- This increased melting point is also carried over to the esters such as the polyhydric alcohol esters such as ester gum prepared from the treated rosin.

This invention has as its object to provide an improved process for the recovery of resin acids' (Cl. 26o-97) may be extracted with-a solution of an alkali salt of a weak inorganic acid in a suitable solvent such as water which is capable of immiscibility with the organic solvent, whereupon the resin acids are subsequently extracted from the alkaline salt solution by an organic solvent which is likewise capable of immiscibility with the alkaline salt solution. The resin acids taken up by thislast solvent are then recovere by evaporation of the organic solvent.

As the raw material I may employ any type of rosin such as wood rosin, gum rosin, socalled non-crystallizing gum rosin, heat treated rosin, isomerized rosin, etc. Instead Iof gum rosin, I may use a solution thereof in turpen- 'tine such as the naturally occurring crude or chemically modied rosin such as dispropor-L tionated rosin which is known as "Hyex rosin and which is rosin which has been heated Lwith a hydrogenating catalyst, but in thev absence of hydrogen (U. S. patent to Littmann, 2,154,629), polymerized rosin, hydrogenated rosin, etc.

As the solvent for the rosin or modied rosin I prefer to use a lower aliphatic ether, that is, an ether in which the number ofcarbon atoms in the alkyl groups is not greater than six, and which is immiscible with water at ordinary temperatures. I have found diethyl ether to be particularly satisfactory. Examples .of other suitable ethers are di-isopropyl ether, di npropyl ether, dibutyl ether, methyl propyl ether, methyl butyl ether, ethyl propyl ether, ethyl butyl ether, b-b-dichloroethyl ether etc.

Instead of using a lower aliphatic ether as the solvent for the rosin or modified rosin, I may use other solvents such as liquid aromatic hydro'carbons such: as benzene, toluene, xylene, coal tar naphtha, etc., petroleum hydrocarbon solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, gasoline, kerosene, V. M. 8: P. naphtha, cyclohexane, tetrahydronaphthalene, decahydronapthalene, dipentene, turpentine, chlorinated hydrocarbons such as chloroform, carbon tetrachloride, ethylene dichloride. trichloroethylene, monochlorobenzene, etc. I prefer to use a solvent which is immiscible with or capable of immiscibility with water thus enabling the use of water as` the solvent for the extracting salt. I-

preier to use an ether solvent which is not sublThe produc-' tion of such a reilned rosin may be by anyuoi,v the well-knownnrefining processes such as Hvvith furfural or other selective solvent, selectiveclnjy sorbents, etc. Instead of using rosin, I may use about 12.0.

stantially completely insoluble in water but which is not soluble in water to an extent greater than about 8% by weight such as diethyl ether.

The concentration of the initial solution may vary widely for example from about 10% to about 70% by weight of the rosin or modified rosin based on the weight of the solution.

As th'e extracting agent, I prefer to use ordinary borax, or sodium tetraborate with varying amounts of, or no, water of crystallization. Instead of sodium tetraborate, I may use sodium metaborate or other alkali metal salts of boric acids. Thus, I may use mixtures of alkali hydroxide and ordinary boric acid in varying proportions. I preferv to use an extractant containing alkali in amount equal Ato one-half of the molar amount of boric acid. Thus, I prefer to use sodium tetraborate (which is derived from 2 mols of sodium hydroxide and 4 mols of boric acid) or a mixture of sodium hydroxide and boric acid in the ratio of two mols of sodium hydroxide to four mols of boric acid.

'I'he use of alkali metaborates results in extraction of a higher percentage of the neutral bodies than when alkali metal tetraborates such as borax, or alkali salts of other weak inorganic acids are employed.

Instead of an alkali salt of a boric acid, I may use strong or fixed alkali salts of other weak inorganic acids, such as carbonic acid, sulfurous acid, phosphoric acid, phosphorous acid, etc., provided that the salt when dissolved in water to form a 5% solution has a pH between about 8.0 and about 12. In th'e case of the polybasic inorganic acids, I may use either the neutral or the acid salts provided that the pH of an aqueous 5% solution thereof is between 8.0 and 12.0. Thus, I may use the alkali (sodium, potassium, lithium) carbonates, phosphates, sulfltes, and phosphites, or such acid saltsas the alkali bicarbonates, and the di-alkali monohydrogen phosphates, etc. 'I'he acid, of which the alkali salt is employed, should be readily soluble in water or other solvent employed for the alkali salt, but substantially insoluble in the organic solvent used to dissolve the rosin or modiiled rosin initially and also in the organic extraction solvent used to extract the aqueous salt extract. I find it desirable to use those alkali salts which' are readily soluble in water or other solvent for the alkali salt but which are substantially insoluble in the organic solvent used to dissolve the rosin or modied rosin initially, or to extract the aqueous salt extract.

The extractant is preferably employed in solution in a solvent which is capable of immiscibility with the solvent employed in forming the rosin or modiiled rosin solution and which is a solvent for the extractant and is a non-solvent for rosin, modied rosin or the resin acids present therein. I prefer to use water as the solvent for the alkali salt extractant.

The concentration of the alkali salt solution may vary between wide limits provided that the pH of the solution falls between about 8.0 and Ordinarily it will be preferred to employ a concentration between about 0.5% by weight of the alkali salt and the limit of solubility thereof at the temperature employed but preferably not exceeding 10%. Usually a concentration of from about 1% to about 5% of th'e alkali salt will be employed. The percentages given refer to the anhydrous alkali salt. In the' case of borax, I prefer to use an aqueous solution containing about 5% of the hydrous bo'rax, i. e., the decahydrate.

The amount of the extracting agent employed may vary within wide limits depending upon the extent of completeness of removal of resin acids desired. In general, it may vary from about one-fifth to about fifty parts of the extracting agent to one part of the rosin or modified rosin.

Following th'e initial extraction with the aqueous alkali salt solution the aqueous extract phase containing dissolved or combined resin acids is separated from the rosin or modified rosin solution phase, and extracted with a solvent for the resin acids contained therein. The solvent used in this final extraction should be capable of immiscibility with the alkali salt solution and may or may not be the same as that employed to initially dissolve the rosin or modified rosin. Any of th'e solvents enumerated above may be employed. Again, I prefer to use a lower aliphatic ether, specifically diethyl ether.

The amount of solvent employed in the final extraction may vary within wide limits depending upon its solvent power for resin acids and upon the quantity of resin acids present in the alkali salt solution extract. In general, it may vary between about 5 and about 15 times the weight of extractant (alkali salt) present in the extract.

Following the final extraction with organic solvent the ph'ases are separated in any suitable manner. The solvent phase is evaporated to recover the resin acids dissolved therein 'I'he alkali'salt phase may be employed in a re-extraction of the rafllnate phase obtained from the first extraction. The alkali salt phase may be used over and over in a repetition of the extraction, until it becomes saturated with certain resin acids which are difficultly or not at all` removable by extraction with the organic solvent such as ether.

In the drawing, there is portrayed a flow sheet of the process as applied to polymerized rosin, using aqueous borax as the initial extractant and using ether as the solvent 'both initially for the polymerized rosin and for the final extraction. The polymerized lrosin solution in ether and the borax solution are commingled in the initial extraction step (block 3)', and the phases separated. The extract (block 5) is extracted (block 7) with fresh ether. The extract from this final extraction (block 9) is evaporated to recover the polymerized rosin of high melting point (block l2) and ether (block 11) which' is re-cycled. The rafilnate (block 8) is used to extract the raffinate (block 4) from the first initial extraction. The

extract from the second initial extraction (block 13) is extracted (block 14) with ether as before. The raffinate from the second final extraction (block 14) is again used to extract the raiinate from the second initial extraction, etc., until the borax solution exerts no extracting power whereupon the polymerized resin acids therein may be precipitated therefrom if desired by neutralization with inorganic acid, and a fresh borax solution employed for subsequent extractions. The ultimate residue is rich in neutral bodies derived from the-polymerized rosin.

If desired, fresh lots of borax solution may be used instead of the rafllnates from the final extractions for the re-extraction of the railina's from the initial extractions.

`The extraction may be conducted either batchwise or continuously. Where a continuous procits neutral body content may be decreased by ess is used, a solution of the rosin or modified rosin in -diethyl ether may be contacted continuously either countercurrently or concurrently with the aqueous borax solution in a. suitable packed tower, the aqueous extract being then passed into another tower Where it continuously contacts fresh ether. The resulting ether extract is then evaporated to recover the extracted rosin acids and the aqueous borax raflinate is recycled back to the rst tower.

The mechanism of the process probably involves the following equation:

AbOH +RX22AbOR-l-HX where AbOH is a resin acid, RX is a strong alkali salt o1' a weak acid, AbOR is an alkali salt of a resin acid and HX is a weak inorganic acid soluble in water but insoluble in the organic extraction solvent. When the rosin solution is contacted with the RX solution, the equilibrium is shifted to the right so that AbOR is formed to some 'extent and HX is formed in solution. When the aqueous solution is separated and contacted with fresh solvent, the resin acid is taken up by the organic solvent so that the equilibrium is shifted back to the left. In this manner, the solution of alkali salt is substantially freed of resin acid and can be used over and over. In practice, however, some rosins and modified rosins such as for example unrefined or FF wood rosin contain small amounts of so-called strong acids which combine with the RX solution and are not completely or are not at all extracted by fresh organic solvent. This difficulty is overcome by using a fresh RX solution after the first several extractions. fresh RX solution can be used over and over after the' so-called strong acids have been removed by the rst few extractions. The RX` solution thus acts as a carrier for the resin acids, carrying them from a solvent containing a high concentration of resin acids to a solvent containing little or no resin acid. 'I'he process of the present invention then'is one in which there is no or only very little consumption of chemicals.

'I'he process of the present invention has an additional advantage over other processes for segregating resin acids in that the acids isolated comprise a mixture which is essentially noncrystalline and non-crystallizing. A further advantage is that the alkali solution carrier can be used over and over. A still further advantage is that no or only minor amounts of mineral acid are required for neutralization which is to be contrasted with the amounts required when NaOH, for example, is used for the extraction of resin acids.

Desirably, I may subject to selective solvent rening the resin acids recovered from the ilnal extract. Thus, I may treat with an immiscible selective solvent for color bodies, such as furfural, phenol, etc., a solution of the recovered rosin acids either in the final extract solution or redissolved ln a suitable solvent such as light petroleum distillate. This step is particularly suitable where an unrened rosin was originally taken.

By selective solvent refining the product in this way, I produce a product even lighter in color and still richer in resin acids and lower `in neutral bodies. v

The residual rosin or modified rosin rich in neutral bodies may also be refined. If desired,

They

distillation, alkaline extraction, etc.

The products produced by the present invention are new so far as I 'am aware. Thus, when the invention is applied to rosin such as ordinary wood rosin, the extracted rosin acids constitute an improved rosin which has great freedom from crystallizing tendencies. a drop melting point above 87 C., an acid number of from 175 to 180, and an unsaponiflable content less than 5%. When the invention is applied to polymerized rosin such as ordinary polymerlzed wood rosin, an improved polymerized rosin is obtained from the extract, having a drop melting point above C., and acid number of from 177 to 185 and a content of unsaponiable matter less than 5%. The residual rosin, also believed to be new, is

characterized by a neutral body vcontent oi' at, vleast 15%, an acid number of less than 155, and

an unsaponiflable content of at least 10%'. 'I'he numerical values of these'l characteristics of the residual rosin will depend upon the extent of the extraction. Thus, if the extraction is very pro,- longed, the residue will consist chiefly of neutral bodies and will be a soft liquid.

The product obtained by treatment by hydro- 'genated rosin in accordance with the invention -Thus where sulfuric acid is present in crude polymerized rosin, application of the process of the present invention enables its ready separation from the polymerized rosin acids. The sulfuric acid and complexes thereof are so strong that they stay with the borax or other extracting salt andare nonextractable by the ether or other extracting solvent used in the final extraction.

The polymerized rosin product is also obtained -by subjecting an extracted non-crystalline rosin product of drop melting point above 87 C., acid number above 117 and Junsaponiiiable content below 5%, such as prepared by the process herein disclosed, to polymerization by means of a rosin polymerization catalyst under polymerizing conditions, and recovering the polymerized product. The polymerization step may thus be carried out before or after extraction, i. e., in any stage of the process in which the rosin is in a non-aqueous phase.

Below are given a number of specific examples of modes of carrying the invention into practice.

Example 1 Two hundred and fty parts by weight FF wood rosin were dissolved in 700 parts by weight diethyl ether and extracted-with 1000 parts by weight 5% borax (pH-9.0). The borax extract was then extracted with 700 parts by weight diethyl ether. The first two portions of borax were used for four extractions, then fresh borax was used over and over' for the subsequent extractions. The combined borax extractions after ether extraction were acidifled to precipitate those acids which could not be removed from the borax by extraction with ether. These co-called strong acids amounted to 10 parts by weight.

The ether which was used for extracting the borax solutions on evaporation yielded:

borax solution was then extracted with 870 parts by weight of toluene. The extraction with borax First 4000 parts by weight borax solution yielded 58. 8 parts by weight resin acids Second 4000 parts by weight borax solution yielded 45. 2 parte by weight resin acids 'lliird 4000 parts by weight borax solution yielded 12. 5 ports by weight resin acids Fourth 4000 parts by weight borax solution yielded 2. 2 parts by weight resin acids Fifth 4000 parts by weight borax solution yielded 1. 6

Total boraxextractable acids 120. 3

The borax extractable acids were reilned by washing a 20% solution in narrow range gasoline (B. R. 20G-270 F.) with 40 parts by weight off Two hundred and nity parts by weight of a polymerized rosin melting at 98-99 C. (drop method) and having an acid number 154.5155.5 were dissolved in 700 parts by weight of diethyl ether and extracted as in Example 1. The yield of resin acids was as follows:

First 4000 parts borax solution yielded 51. 1 parts resin acid Second 4000 parts borax solution yielded 30.0 parts resin acid Third 4000 parts borax solution yielded 1.8 parts resin acid Fourth 4000 parts borax solution yielded 2.0 parts resin acid Total borax extractable acids 84.9 parts by weight I The melting point of the acids was 104.7 (drop method). 'I'lie acid number was 177.0, the saponiiication number was 180.7 and the thiocyanogen number was 68.2.

Example 3 Two hundred and fifty parts by weight of a heat treated rosin in 350 parts by weight of diethyl ether was extracted with 500 parts by weight of 5% borax as in Example 1. The borax kextracts were each washed with 350 parts by weight of diethyl ether to remove the resin acids. The yields of acids were as follows:

First 4000 parts borax solution yielded 69. 6 parts by weight resin acid Second 4000 parts borax solution yielded 37. parts by weight resin acid Third 4000 parts borax solution yielded 16. 8 parts by weight resin l. 3 parts by weight resin acid Fourth 4000 parts borax solution yielded Total 124.

The melting point of the acids was 87.7 C., the acid number was 174.7, and the saponication number was 181.5.

Example 4 Five hundred parts by weight I gum rosin (M. P. 86 C.) were dissolved in 350 parts by weight diethyl ether and extracted with 500 parts by weight of 5% borax solution. The borax extracts were each washed with 350 parts by weight of ether to remove the resin acids. The extraction was carried out as in Example 1, 32 extractions being made. The resin acids were recovered by evaporation of the ether. The total amountl of resin acids thus obtained amounted to 433 parts by Weight. The melting point of the acids was 91 C. The ester gum of the acids melted at 101 C. V

Example 5 Two hundred and fty parts by weight of wood rosin were dissolved in 870 parts by weight oi toluene and the solution extracted with 1000 parts by weight of 5% borax solution. The

acid

parts by weight resin acids and extraction of the borax solution with toluene waserepeated three times. From 4000 parts by weight of borax extract there was thus obtained 3.2 parts by weight of resin acid.

, Example 6 Five hundred parts by weight I wood rosin were dissolved in 1250 parts by weight of petroleum ether. This solution was extracted with 2000 parts by weight 5% borax. The borax solution was then extracted with 1250 parts by weight of petroleum ether. This extraction with borax and Vextraction of the borax with petroleum ether was repeated again. From the petroleum ether there was obtained by evaporation 3.3 parts by weight of resin acid.

Example 7 Fifth 4000 parts by weight borax yielded Sixth 4000 parts by weight borax yielded 1.4 parts resin acid Total 174. 8

The melting point of the acids was 89.5 C., the acid number was 176.9, the saponification number 86.6 parts resin acid 71.4 parts resin acid ll. 5 parts resin acid 2.0 parts resin acid 1.9 parts resin acid was 178 and the thiocyanogen number was 92.2. l

The ester gum of the acids melted at 97 C.

Example 8 Two hundred and iifty parts by weight of hydrogenated wood rosin (melting point 79 C.) were extracted as described in Example 7. The total weight of resin acids removed amounted to 149.1 parts by weight. The resin acids had a melting Vpoint of 83.7 C. (drop method), and an acid number of 174.0, a saponiiication number of 176.7, and a thiocyanogen number of 28.0. The ester gum of the acids melted above C.

Example 9 A solution of 250 parts by weight of K wood rosin in 300 parts by weight diethyl ether was agitated with four portions of 5% Na3PO4.12HzO solution (pH 11.0) amounting to 500 parts by weight each. After complete separation into two layers, the trisodium phosphate layers were separated and each extracted with one portion of diethyl ether amounting to 300 parts by weight. The resulting 1200 parts by weight of diethyl ether were evaporated to obtain the resin acids which amounted to 9.0 parts by weight.

Example 10 By substituting 3.4% sodium metaborate solution (pH 9.35) for the trisodium phosphate solution in Example 9, a yield of 154 parts by weight of resin acid was obtained from the 1200 'parts by weight of diethyl ether. The resin acid was much higher in neutral body content,- however.

Ezample 11 Example 13 By substituting- 3% NazCOaBHzO solution (pH 10.7) for the trisodium phosphate solution in Example 9 and carrying out two of the extraction processes outlined in Example 9, the yield of resin acid from 600 parts by weight of diethyl ether was 19.1 parts by weight.

Example 14 Five hundred parts by weight crude pine oleoresin" were dissolved by gentle heating with 250 parts by weight diethyl ether. The solution was ltered to remove water and foreign matter. 'I'he filtrate was extracted with 500 parts by weight oi borax solution. The borax extract was washed with 350 parts by weight of ether to remove the resin acids. The extraction was repeated as in Example 1, thirty-two extractions being made. The resin acids were recovered by evaporation of the ether extracts.

Example 15 Five hundred parts by weight of so-calle'd noncrystallizing gum rosin (prepared by the method of Palkin et al., U. S. P. No. 2,176,660) was commingled with 350 parts by weight diethyl ether and the solution extracted with 500 parts by weight of 5% borax solution, as in Example 1, thirty-two extractions being made. 'I'he extracts were extracted with ether as before and the ether extracts evaporated to recover the extracted rosin acids. This constituted a wayof obtaining an improved gum rosin low in unsaponiflable from a gum rosin containing a. larger content of unsaponiable than average gum rosin, since the treatment of Palkin et al. markedly increases the unsaponiiiable content.

As used in this specication and in the claims appended hereto, the term modiiied rosin refers to ordinary rosin which has been treated so as to chemicallyv change its rosin nucleus without substantially aecting its carboxylic acid grouping, as for example by heat treatment, isomerization, hydrogenation, polymerization, disproportionation, etc. The term solvent capable of immiscibility is used to include solvents which either are immiscible or may be madeVU immiscible as by changing the temperature.

This application is a continuation-in-part of my copending application, Serial No. 381,779, led March 5, 1941.

It will be understood that the details and examples hereinbefore set :forth are illustrative only and that the invention as broadly described and claimed is in no way limited thereby.

What I claim and desire to protect by 4Letters Patent is:

v1. The process or refining polymerized rosin products* which comprises bringing into contact a solution of a polymerized rosin and an aqueous solution capable oi' immiscibility therewith of an inorganic alkaline salt of an alkali metal, the said solution having a pH between about 8 and about 12, extracting acidic components from the initial polymerized rosin solution into the alkaline salt solution, separating the salt solution from the polymerized rosin solution, bringing the salt soluf tion into contact with -a. solvent capable oi.' immiscibility therewith, the said solvent being a solvent for polymerized rosin acids but substantially non-solvent for the alkali metal salt, the acid thereof. and the alkali salt-polgfirmeiized,I vrosin acidextraetion product, extracting polyvmerized rosin acids from the salt solution into the solvent immiscible therewith, and separating the resulting solvent phase containing extracted polymerized rosin acids from the salt solution.

2. The process of refining polymerized rosin products which comprises bringing into contact a lower aliphatic ether solution of a polymerized rosin and an aqueous solution capable of immiscibility therewith 'of an inorganic alkaline salt of an alkali metal, the said solution having a pH between about 8 and about 12, extracting acidic components from the initial polymerized rosin solution into the alkaline salt solution, separating the salt solution from the polymerized rosin solution, bringing the salt solution into contact with a lower aliphatic ether, extracting polymerized rosin acids from the salt solution into the lower aliphatic ether, and separating the resulting ether yphase containing extracted polymerized rosin acids from the salt solution.

3. The process of refining polymerized rosinr products which comprises bringing into contact a solution of a polymerized rosin and an aqueous solution capable of immiscibility therewith of a salt of a boric acid and an alkali metal, the said borate solution having a pH between about .8 and about 12, extracting acidiccomponents from v the initial polymerized rosin solution into the borate salt solution, separating the borate salt solution from the polymerized rosin solution. bringing the borate salt solution into contact with a solvent capable of immiscibility therewith, the

said solvent being a solvent for polymerized rosin metal borate-polymerized rosin acid extraction product, extracting polymerized rosin acids from the borate saltvsolution into the solvent immiscible therewith, and separating the resulting solvent phase containing extracted polymerized rosin acids from the borate salt solution.

4. Theprocess of refining polymerized rosin products which comprises bringing into contact a lower aliphatic ether solution of a polymerizedI rosin and an aqueous solution capable of immiscibility therewith of a salt of a boric acid and an alkali metal, the said solution having a pH between about 8 and about 12, extracting acidic components from the initial polymerized rosin solution into the borate salt solution, separating the borate salt solution from the polymerized rosin solution, bringing the borate salt solution into contact with a lower aliphatic ether,

extracting polymerized rosin acids from the borate salt solution into the lower aliphatic ether, and separating theresulting ether phase containingextracted polymerized rosin acids from the borate salt solution.'

5. The process of reiining polymerized rosinl products which comprises bringing into contact a lower aliphatic ether solution of a polymerizedrosin and an aqueous solution capable of immiscibility therewith of a salt of a boric acid and an alkali metal, the said solution having a pH between about 8 and about 12, extractingVv acidic components from theinitial v polymerized separating the resulting ether phase containing extracted polymerized rosin acids from the borate salt solution.. and'further extracting polymerized rosin ether solution with the ether extracted aqueous alkali metal borate solution.

6. The process of rening a polymerized rosin which comprises bringing into contact a solution of the polymerized rosin and an aqueousvsolution capable of immiscibility therewith of a salt of a boric acid and an alkali metal, the said solution having a pH between about 8 and about 12, extracting acidic components from the polymerized rosin solution into the borate salt solution, separating the borate salt solution from the polymerized rosin solution, bringing the borate salt solution into contact with a lower aliphatic ether, extracting polymerized rosin acids from the borate salt solution into the lower. aliphatic ether, separating the resulting ether phase containing extracted polymerized rosin acids from the borate salt solution, and recovering a polymerized rosin .product of increased melting point from the ether solution.

tracted polymerized msm acids from the borate salt solution, and recovering a polymerized rosin product of increased melting point from the ether solution.

9. The process of which comprises bringing into contact a lower aliphatic ether solution of the polymerized rosin and an aqueous solution immiscible therewith of afsodium metaborate, the said solution having a pH between about 8 and about l2, extracting acidic components from the polymerized rosin solution into the borate salt solution, separating the borate salt Asolution from the polymerized rosin solution, bringing the borate salt solution into contactwith a lower aliphatic ether, extracting polymerized rosin acids from the borate salt solution into' the lower aliphatic ether, separating the resulting ether phase containing-extracted polymerized rosin acids from the borate salt solution, and recovering a polymerized rosin product -of increased melting point v from the ether solution.

` 10. The process of reilning a polymerized rosin which comprises bringing into contact a solution of the polymerized rosin in diethyl ether and an aqueous solution capable of immiscibility therewith of a sodium salt of a boric acid having a conicentration between about 0.5% and about 7; The process of refining a polymerized rosin which comprises bringing intocontact a lower aliphatic ether solution of the polymerized rosin and an aqueous solution immiscible therewith of a sodium borate, the said solution having a pH between about 8 and about 12, extracting acidic components from the polymerized rosin solution into the borate salt solution, separating the borate salt solution'from the polymerized rosin solution, bringing the borate salt solution into contact with a lower aliphatic ether, ex-

tracting polymerized rosin acids from the borate salt solution into the lower aliphatic ether, separating'the resulting ether phase containing extracted polymerized rosin acids from .the borate salt solution, and recovering a polymerized rosin product of increased melting point from the ether solution.

8. The process of refining a polymerized rosin which comprises bringing into contact a lower aliphatic ether solution of the polymerized rosin and an aqueous solution immiscible therewith of a sodium tetraborate, the said solution having a pH between about 8 and about 12, extracting acidic components from the polymerized rosin solution into the borate salt solution, separating 10% of the said salt and a pH between about 8 and about 12, extracting acidiccomponents from the polymerized rosin solution into the borate salt solution, separating the borate salt solu.

tion from the polymerized rosin solution, bring.- ing the borate salt solution into contact with diethyl ether, extracting polymerized rosin acids from the borate salt solution into the ether, separating the resulting ether phase containing extracted polymerized rosin acids from the borate salt solution and recovering a polymerized rosin product of increased melting point from the ether solution.

11. The process of preparing a refined polymerized rosin which comprises forming a solution of rosin, bringing into contact the rosin solution and an aqueous solution capable of immiscibility therewith of an inorganic alkaline salt of an alkali metal, the said solution having a pH between about 8 and about 12, extracting acidic components from the rosin solution into the salt solution, separating the salt solution from the rosin solution, bringing the salt solution into Contact with a solvent capable of immiscibility therewith, the said solvent being a solvent for the rosin acids present but substantially non-solvent for the alkali metal salt, the inorganic acid thereof, and the alkali'metal saltrosin acid extraction product, extracting rosin merized rosin product consisting essentially of a non-crystalline mixture of polymerized rosin acids derivable from'polymerized rosin, said polythe borate salt solution from the polymerized rosin solution, bringing the borate salt solution into contact with a lower aliphatic ether, extracting polymerized rosin acids from the borate salt solution into the lower aliphatic ether, separating the resulting ether phase containing exmerized rosin product having a drop melting point above C., an acid number of from 177 to 185, and a content of unsaponiflable matter less than 5%.

RICHARD F. B. COX.

refining a polymerized rosinv 

